I'm trying the following logic and not sure which array function can help. I'm not able to use map or es6 but would like to see an answer.
I tried the following:
/* JS */ - This is not working and would like to see how to make it work.
var input = ['x','y','z'];
var powerSetResult = powerSet(input);
console.log(powerSetResult);
/*Ouput should be [''.'x','y','z','xy,'xz','yz','xyz']*/
function powerSet(arr) {
var data = [];
for(var i=0; i<arr.length; i++) {
arr[i] = arr[i] + arr[i+1];
data.push(arr[i]);
}
console.log(data);
return data;
}
/* ES 6 */ - Is there a better way to do this?
let input = ['x','y','z'];
let powerSetResult = powerSet(input);
console.log(powerSetResult);
/*Ouput should be [''.'x','y','z','xy,'xz','yz','xyz']*/
const powerSet(arr) {
let data = arr.map(([s1, s2, s3]) => [``,`${s1}`,`${s2}`,`${s3}`,`${s1}${s2}`,`${s1}${s3}`,`${s2}${s3}`,`${s1}${s2}${s3}`]);
console.log(data);
return data;
}
Certainly not the most efficient... but you could do this:
var input = ['x','y','z'];
var powerSetResult = powerSet(input);
console.log(powerSetResult);
function powerSet(arr, result) {
result = result || new Set();
const str = arr.join('');
for (let i = 0; i < arr.length; i++) {
for (let j = i; j <= arr.length; j++) {
result.add(str.slice(i, j));
}
powerSet([...arr.slice(0, i), ...arr.slice(i+1)], result)
}
return Array.from(result).sort((a, b) => {
return (a.length - b.length) || a.localeCompare(b);
});
}
/* Output should be [''.'x','y','z','xy,'xz','yz','xyz'] */
Caveat being it will only work for single letter elements, but is easily modifiable to accommodate more.
Related
I want to condition the string that I Inputted value ("ello") and variable("hello").
If It found in string("hello"), the return value should be "ello".
If not found, the return value should be -1.
But it returned "llll" 4 times because of condition (strs[i] == arrayS[tempVal]).
How can I get the correct answer as mentioned above?
var stres = "hello";
var strs = [...stres];
function searchStr(s) {
let arrayS = [...s];
let tempVal = 0;
let tempStr = [];
while (tempVal < arrayS.length) {
for (let i = 0; i < strs.length; i++) {
if (strs[i] == arrayS[tempVal]) {
tempStr.push(arrayS[tempVal]);
}
}
tempVal++;
}
return tempStr;
}
const res = searchStr("ello");
console.log('res', res)
According to you, logic is correct just break the for a loop when the condition is fulfilled. Check below snippet and console output.
var stres = "hello";
var strs = [...stres];
function searchStr(s) {
let arrayS = [...s];
let tempVal = 0;
let tempStr = [];
while (tempVal < arrayS.length) {
for (let i = 0; i < strs.length; i++) {
if (strs[i] == arrayS[tempVal]) {
tempStr.push(arrayS[tempVal]);
break;
}
}
tempVal++;
}
return tempStr;
}
const res = searchStr("ello");
const resS = res.join('');
console.log('res = ', res);
console.log('resS = ', resS);
how can i get elements uniquely from an array if aa is twice time it should not count in a result if it is if a is three times it should count 1
var string = "aaabbccddde" // Expected result ade
var toArray = string.split("")
console.log(toArray)
var newArr = []
for(let i =0; i<toArray.length; i++) {
if(newArr.indexOf(toArray[i]) === -1) {
newArr.push(toArray[i])
}
}
console.log(newArr)
can't find the solution yet please guide thank
Maybe this function can help you:
function getUniques(str) {
const uniques = [];
const strs = str.split("");
for (let i = 0; i < strs.length; i++) {
const elm = strs[i];
for (let j = i; j < strs.length; j++) {
if(elm === uniques[uniques.length - 1]) break;
if (elm !== strs[j + 1]) {
uniques.push(elm);
break;
}
}
}
return uniques.join("");
}
Sample:
getUniques("aaaadaaabbbcccdeeeee22222222222232") // adabcde232
I know it's a stupid question, but I only learning programming 3 months now.
How would you solve this problem, if you can't use higher order functions and built-in methods, like filter or indexOf?
Create a function that takes a list of numbers and returns a new list where all the duplicate values are removed
I got this so far, but I think It's a dead end...
const array = [1, 2, 3, 3, 1];
const removeDuplicate = () => {
let shortArray = [];
let index = 0;
for (let i = 0; i < array.length; i++) {
for (let j = 0; j < array.length; j++) {
if (i != j) {
if (array[i] == array[j]) {
shortArray[index] += array[i]
console.log(array[i]);
}
}
}
}
return shortArray;
}
console.log(removeDuplicate());
return this:
1
3
3
1
[ NaN ]
thanks!
Use an object as a helper. If a value appears in the helper, it's not unique and can be ignored. If it's not in the helper it's unique, push it into the result array, and add it to the helper object.
const array = [1, 2, 3, 3, 1];
const removeDuplicate = (arr) => {
const helperMap = {};
const result = [];
for (let i = 0; i < arr.length; i++) {
const item = arr[i];
if (!helperMap[item]) {
result[result.length] = item;
helperMap[item] = true;
}
}
return result;
};
console.log(removeDuplicate(array));
function unique(arr) {
var obj = {};
for (var i = 0; i < arr.length; i++) {
var value = arr[i];
obj[value] = true; // set as key
}
return Object.keys(obj); //return all keys
}
Use below function:
function RemoveDuplicate(array){
let shortArray = [];
let index = 0;
for (let i = 0; i < array.length; i++) {
let exist=false;
for(let j=0;j<shortArray.length;j++){
if(array[i]==shortArray[j]){
exist=true;
break;
}
}
if(!exist){
shortArray[shortArray.length]=array[i];
}
}
return shortArray;
}
My web app is taking in arbitrarily large 2D arrays that sometimes look something like this:
var multiArray = [["","","",""],[1,2,3],["hello","dog","cat"],["","","",""]];
I want to write a function to take out every array inside of multiArray that is comprised entirely of quotes. In other words, any array that looks like this:
["","","",""]
should be deleted from multiArray.
I tried writing the following function, but the problem with using splice in a for loop is that splicing will change the length of the array, and I end up trying to access undefined elements. Please help!
Thanks!
Here's the incorrect function I wrote:
function cleanWhitespace(arrayOfArrays) {
var i;
var arrayOfArraysLength = arrayOfArrays.length;
for (i = 0; i < arrayOfArraysLength; i++) {
var cleanedArray = $.grep(arrayOfArrays[i], function(element) {
return element != ""
});
if (cleanedArray.length == 0) {
arrayOfArrays.splice(i, 1);
}
}
return arrayOfArrays;
};
You can use $.grep :
multiArray = $.grep(multiArray, function(v){
return v.join('');
});
Fiddle : http://jsfiddle.net/scZcB/
on the fly:
var multiArray = [["","","",""],[1,2,3],["hello","dog","cat"],["","","",""]];
var outputArr = removeQuoteArrays(multiArray);
console.log(outputArr);
function removeQuoteArrays(arr) {
var outputArr = [];
for (var i = 0; i < arr.length; i++) {
var currArr = arr[i];
var isAllQuotes = true;
for (var j = 0; j < currArr.length; j++) {
if (currArr[j] != "") {
isAllQuotes = false;
break;
}
}
if (!isAllQuotes) {
outputArr.push(currArr);
}
}
return outputArr;
}
Here's a JSFiddle.
Create a new array instead.
// Only add if...
cleanedArray = multiArray.filter(function(arr){
// Some elements are not blank
return arr.some(function(e){ return e !== "" })
})
I added a length check to your function to break out of the loop if the index reaches the array length:
if (i >= arrayOfArrays.length)
break;
Which makes:
function cleanWhitespace(arrayOfArrays) {
var i;
var arrayOfArraysLength = arrayOfArrays.length;
for (i = 0; i < arrayOfArraysLength; i++) {
var cleanedArray = $.grep(arrayOfArrays[i], function(element) {
return element != ""
});
if (cleanedArray.length == 0) {
arrayOfArrays.splice(i, 1);
if (i >= arrayOfArrays.length)
break;
}
}
return arrayOfArrays;
};
var multiArray = [["","","",""],[1,2,3],["hello","dog","cat"],["","","",""]];
function cleanWhitespace(arrayOfArrays) {
for (var i = 0; i < arrayOfArrays.length; i++) {
var emptyElements = 0;
for (var j = 0; j < arrayOfArrays[i].length; j++ ) {
if (arrayOfArrays[i][j] === "") {
emptyElements++;
}
}
if (emptyElements === arrayOfArrays[i].length) {
arrayOfArrays.splice(i, 1);
}
}
return arrayOfArrays;
}
console.log(cleanWhitespace(multiArray));
http://jsfiddle.net/4Jfr9/
I create an array like so
var membersList = $('#chatbox_members' , avacweb_chat.doc.body).find('li');
var onlineUsers = [];
var offLineUsers = [];
for(var i =0;i<membersList.length;i++){
var name = $(membersList[i]).text().replace("#","");
onlineUsers.push(name);
}
alert(onlineUsers);
listedUsers would come out something like so [Mr.EasyBB,Tonight,Tomorrow,Gone];
Question is if I use a two for loops one outside a setInterval and one inside to compare-
var membersList = $('#chatbox_members' , _chat.doc.body).find('li');
var onlineUsers = [];
var offLineUsers= [];
for(var i =0;i<membersList.length;i++){
var name = $(membersList[i]).text().replace("#","");
onlineUsers.push(name);
}
var int = setInterval(function() {
var newMember = ('#chatbox_members' , _chat.doc.body).find('li');
for(var i =0;i<newMember.length;i++){
var name = $(newMember[i]).text().replace("#","");
offLineUsers.push(name);
}
Which then would get:
onlineUsers = [Mr.EasyBB,Tonight,Tomorrow,Gone];
offLineUsers = [Mr.EasyBB,Tonight];
So to get the offline users I want to basically replace onlineUsers with offLineUsers which then should return Tomorrow,Gone . Though I know that an object doesn't have the function to replace so how would I go about this?
I don't think the splice function would work since you need to have parameters, and pop or shift are beginning and end of array.
for(var i = 0 ; i < offLineUsers.length ; i++)
{
for(var j = 0 ; j < onlineUsers.length ; j++)
{
if(onlineUsers[j] == offLineUsers[i])
{
onlineUsers.splice(j,1);
}
}
}
Try this snippet.
If I have understand well, maybe that helps:
function bus_dup() {
for(var i = 0; i < offLineUsers.length; i++) {
onLineUsers.splice(onLineUsers.indexOf(offLineUsers[i]),1);
}
offLineUsers = [];
}
This should do what you are looking for on a modern browser, using array.filter
var onlineUsers = ["Mr.EasyBB", "Tonight", "Tomorrow", "Gone"];
var offLineUsers = ["Mr.EasyBB", "Tonight"];
function discord(online, offline) {
return online.filter(function (element) {
return offline.indexOf(element) === -1;
});
}
console.log(discord(onlineUsers, offLineUsers));
Output
["Tomorrow", "Gone"]
On jsfiddle
If you want the difference regardless of the order of attributes passed to the function then you could do this.
var onlineUsers = ["Mr.EasyBB", "Tonight", "Tomorrow", "Gone"];
var offLineUsers = ["Mr.EasyBB", "Tonight"];
function difference(array1, array2) {
var a = array1.filter(function (element) {
return array2.indexOf(element) === -1;
});
var b = array2.filter(function (element) {
return array1.indexOf(element) === -1;
});
return a.concat(b);
}
console.log(difference(onlineUsers, offLineUsers));
console.log(difference(offLineUsers, onlineUsers));
Output
["Tomorrow", "Gone"]
["Tomorrow", "Gone"]
On jsfiddle